1. Field of the Invention
The present disclosure relates to photodiode arrays (PDAs), and more particularly to a unit pixel construction for photodiode arrays.
2. Description of Related Art
Traditional pixels made up of diodes (PN, PiN, Avalanche diodes, etc.), such as those used in photodiode arrays, contribute to the dark current and capacitance of the overall PDA. Pixel dark current and capacitance are key factors in determining the pixel performance. Lower values tend to indicate better pixel performance which ultimately translates to better signal to noise ratios at the overall camera and system levels. Pixel dark current and capacitance are significant contributors to the overall camera level noise. The unit pixel design plays a significant role in defining these contributing parameters to system level noise.
Such conventional pixel designs have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved designs.